Presently, spring contacts are applied in electricity system and high voltage switch fields, and mostly are applied in transmission and transformation lines for electrical connecting. There are various types of specific configurations for point contacts in electricity systems and high voltage switch facilities. Based on whether there are relative movements in point contact portion during operating, such configurations can be divided into three main types: sliding connecting, static connecting and plug-in connecting. In sliding connecting, a movable contact can slidably move with respect to a static contact, but they do not separated from each other. In static connecting, during working period, a movable contact and a static contact immovably contact together, while not moving with respect to each other and separating from each other, two or more conductor connecting portions of which are fixed by fastener pressing mechanical method, for example, such as bolts, threads, or rivets and so on. In plug-in connecting, a movable contact and a static contact can be separated from each other or come into contact together at any time. Such connecting is typically used for connecting or shutting off circuits in idle load, normal load or short circuit conditions. Above-mentioned three connecting types typically include several portions, i.e. conducting circuits, which are loaded with electrical current; separable contacts, on which spring contacts are installed; arc-control devices, which allow for extinguishing arc quickly so that circuits are finally cutout, however, generally speaking, are not provided for a high voltage isolating switch dedicatedly; driving mechanisms; operating mechanisms and so on. It is noted that, and when a high voltage switch are properly at ON position, sufficient contact pressure to the contact head is only depended on pressing or pulling actions of the spring contact.
Currently, one type configuration for a plug-in high voltage switch contact, as is shown in FIG. 1, is widely used, which includes a static contact 100, a movable contact 101, and a spring contact 102. The spring contact 102 is generally positioned in an annular groove of a static contact 100 (rarely is set in a groove of a movable contact). The movable contact 101 can move up and down in the static contact 100 until it falling off from the static contact 100. Such configuration is based on a principle as follows: a movable contact 101 comes into tight contact with a static contact 100 at point A and B through elastic deformation of the spring contact 102, and point C is only used to define position of the spring contact 102, without undertaking contacting pressure. Thus, current is allowed to flow from point A to point B of the spring contact 102, so that current circulation is achieved. The spring contact is a critical factor for such configuration, so that it is required to process good elastic property and reasonable configuration, so as to secure stable contact, uniform current and reasonable temperature rising property. Sliding connecting and static connecting are based on the same principle as above.
However, there are several disadvantages in prior spring contacts:                1. From FIG. 1(a), it can be seen that a spring contact comes into contact with a movable contact and a static contact respectively only at one point, and only one half arc passes each point, as a result, there is a limit of current passing capacity;        2. The single ring cross section of the spring contact is circular, which takes up more space;        3. The groove for installing is not reasonable, because its path for current passing is longer, and resistance at a single point is bigger, which is not an optimized mode;        4. Its current passing capacity is limited, circular cross section area is bigger, and configuration for installing is not reasonable, which cannot satisfy requirements for a compact and simple spring contact, as a result, prior spring contacts are only applied in high voltage switch field.        